Older adults are the fastest growing segment of the U.S. population, with the number of adults age 65 or older expected to grow to 70.3 million in 2030. Among this group, hearing loss is the third most prevalent chronic medical condition, with some 40-45% of adults over the age of 65 showing some degree of hearing impairment, rising to 83% in the population over the age of 70. Although considerable progress has been made in both audition and cognitive aging research, hearing loss has primarily been considered as an independent issue. This competing renewal builds on ten years of research investigating sensory-cognitive interactions as they affect spoken language comprehension and memory in adult aging. A major concern of both theoretical and practical importance is that even with a mild hearing loss, the perceptual effort older adults must expend on decoding a degraded speech signal will draw attentional resources that would otherwise be available for higher-level sentence comprehension and encoding what has been heard in memory. As such, a memory or comprehension deficit in many older adults may have an unrealized sensory origin. We propose a program of research to elucidate the mechanisms that may underlie the effect of perceptual effort on comprehension and memory for spoken information. We test a hypothesis that acuity-related listening effort, along with age-related changes in working memory and executive function, lead to a qualitative change in how sentences and discourse are processed, with results that can lead to both comprehension successes and failures. Successful outcome of this research will advance our understanding of cognitive aging at the level of theory, but also with implications for improving communicative effectiveness in older adulthood. PUBLIC HEALTH RELEVANCE: Adult aging represents a balance of decline and compensation. Nowhere is this balance more important than in the ability to understand, and recall the content of, meaningful speech. When cognitive aging is accompanied by even a mild-to-moderate hearing loss, the result can be devastating to communicative effectiveness between the older adult and health care and social service providers, as well as leading to social isolation from family and friends. This research program is designed to close a critical gap in our knowledge of the interacting effects of cognitive aging and age-related hearing loss on everyday speech comprehension in older adults, and may also serve as a framework for early detection of pathological change as it affects language comprehension in the aging brain.